Combination refrigerating appliance and evaporators for same

ABSTRACT

The refrigerating appliance comprises at least one first, second and third refrigerating area for a low, medium or high storage temperature, whereby each refrigerating area has an evaporator ( 24, 25, 26 ). The refrigerating appliance also comprises a compressor ( 19 ), a refrigerant circuit for supplying compressed refrigerant to the evaporators ( 24, 25, 26 ) and for returning expanded refrigerant to the compressor ( 19 ), and comprises at least one switching element ( 22, 22 ′) for directing, as desired, the refrigerant through one of two branches (I, II) of the refrigerant circuit. In the first branch (I), the evaporators ( 24, 26 ) of the first and the third refrigerating areas are connected in series. In the second branch (II), The evaporators ( 24, 25, 26 ) of all three refrigerating areas are connected in series.

[0001] The present invention relates to a refrigerating appliance withat least three refrigerating areas under the preamble of Claim 1 andevaporators for such a refrigerating appliance.

[0002] Such a refrigerating appliance is disclosed in DE 4 242 776 A1.

[0003] This known refrigerating appliance has two valve units located inthe refrigerant circuit and may be activated, in order to channel arefrigerant flow only through an evaporator dedicated to the firstrefrigerating area called a refrigeration compartment, or subsequentlythrough an evaporator dedicated to the second refrigerating areadescribed as standard refrigeration compartment and the refrigerationcompartment evaporator or through a third evaporator dedicated to arefrigerating area described as freezer compartment and therefrigeration compartment evaporator. This means that the refrigeratingappliance has three operating modes, a first in which only therefrigeration compartment is cooled, a second, in which the standardrefrigeration compartment and the refrigeration compartment are jointlycooled, and a third, in which the freezer compartment and therefrigeration compartment are jointly cooled. The operating times mayvary considerably within the three operating modes. Since the chillingdepartment has a relative weak insulation and a small evaporator whencompared to the other compartments, the operating time in the thirdoperating mode may clearly exceed that of the second. This leads to ahigh overall operating time of the refrigerating machine of therefrigeration appliance and therefore to a high-energy consumption andto a lower temperature of the refrigeration compartments than necessary.

[0004] The object of the invention is to define a refrigeratingappliance and evaporators for a refrigerating appliance which enables areduction of the operating time in the third operating mode and therebyprevent super-cooling the refrigeration compartment and reduce theenergy consumption of the refrigerating appliance.

[0005] This problem is solved by a refrigerating appliance with thecharacteristics of Claim 1 and/or evaporators for such a refrigeratingappliance with the characteristics of Claim 6.

[0006] By connecting the evaporators of all three refrigerating areassequentially in the second branch of the refrigerant circuit of therefrigerating appliance or by placing the connections on the evaporatorsso that a series connection of the three evaporators spans between twoof the connections will be achieved that the third refrigerating area,the freezer compartment, will also be cooled when the refrigerant flowis routed over the second refrigerating area, the standard refrigerationcompartment. The freezer compartment is therefore also continuouslycooled when cooling the standard refrigeration compartment, so that theoperating time required to adhere to the holding temperature of thefreezer compartment is reduced in the third operating mode and thereforealso the overall cooling period of the refrigeration compartment.

[0007] On the other hand, in order to now avoid excessive cooling of thefreezer compartment at the expense of the refrigeration compartment, aneffective provision may be made so that the second branch of therefrigerant circuit extends only over a section of the surface of theevaporator of the freezer compartment. The size of this section toobtain adequate cooling in all refrigerating areas at minimum powerconsumption depends on the sections of the individual evaporators and/oron their cooling capacities, as well as on the insulation quality of theindividual temperature sectors. A generally effective rule for the sizeof this surface section can therefore not be defined; however, asuitable value is adjustable per experiment without any difficulty.

[0008] The evaporator of the third refrigerating area may be arranged inthe second branch between the evaporators of the first and the secondrefrigerating area, so that the evaporated refrigerant partially flowsthrough while the maximum cooling capacity per surface unit of theevaporator accumulates in the particular refrigerating area which iscirculated by the refrigerant which is still in a liquid state.

[0009] Appropriately, the refrigerant circuit further has a thirdbranch, which only contains the evaporator of the first refrigeratingarea. This third branch may be used when the cooling capacity, whichreaches the first refrigerating area over the first or the secondbranch, is insufficient to maintain its holding temperature.

[0010] In this case, it may be appropriate that the first and the secondbranch expand over only a section each of the evaporator surface of thefirst refrigerating area. If this method assures that the coolingcapacity which the first and the second branch in the firstrefrigerating area develop is somewhat insufficient to adhere theirholding temperature, so that occasionally an operation of the thirdbranch is required, a super-chilling of the first temperature sectionand the therefore accompanying dissipation of energy is thereforeimpossible.

[0011] Additional characteristics and advantages of the invention resultfrom the description of implementation examples in the following withreference to the added figures, in which:

[0012]FIG. 1 shows a perspective of a household refrigeration appliancewith three temperature areas for which the submitted invention isapplicable,

[0013]FIG. 2 shows the refrigeration system of the refrigerationappliance in FIG. 1 in a simplified, schematic illustration, and

[0014]FIGS. 3 and 4 show examples of evaporators for the refrigerationappliance corresponding with the invention.

[0015]FIG. 1 shows a perspective of a household refrigeration appliance10, whereof the heat-insulated housing 11 is provided with attached anddoors 12-14 which open separately at its opening at the edge of theopening edge. Three compartments, which are superimposed and thermallyseparated by partitions in the interior of the housing 11, are lockableby the doors 12-14 which form the refrigerating areas 15-17 for variousstorage temperatures. The upper refrigerating area which may be lockedby door 12 represents a refrigeration compartment, centre section 16,which is assigned to the door 13, serves as standard refrigerationcompartment, while the section 17 located below is designed as freezercompartment and can be locked with the door 14. The various storagetemperatures in the individual sections are maintained with theassistance of the refrigeration system described in the following.

[0016] The refrigeration system 18 illustrated schematically in FIG. 1has a refrigerant compressor 19 behind which a condenser 20 is locatedon the pressure side. A dehumidifier cartridge 21 connects to the outletof the condenser 20, whose outlet is connected with the inlet of a firstvalve unit 22, which is designed as an electromagnetically operated 3/2way valve. A first outlet of this valve unit is connected to an inlet ofan evaporator 26, which is located in the freezer compartment 17 of therefrigeration appliance. A second outlet of the valve unit 22 isconnected to the inlet of a similar second valve unit 22′, whose twooutlets are always connected with an inlet of an evaporator 25 of thestandard refrigeration compartment 16 and/or an evaporator 24 ofrefrigeration compartment 15. A spirally wound restrictor 23 which isdesigned as capillary tube is connected in series between the inlet ofone of the evaporators 24, 25, 26 and the assigned outlet of a valveunit 22.

[0017] The outlet of the evaporator 25 is connected by a connecting linebetween the inlet of the evaporator 26 and the restrictor 23, which isassigned to it, the outlet of the evaporator 26 is connected in ananalog mode with the inlet of the evaporator 24.

[0018] The refrigerant circuit therefore has three branches, which aredefined as FIG. 1-111. All three branches pass through the evaporator24, which is assigned, to the refrigeration compartment 15. The branchin guides the refrigerant initially through the evaporator 26 of thefreezer compartment 17; branch 111 represents a series connection of allthree evaporators in sequence 25, 26, 24.

[0019] A temperature sensor 27, 27′ and 28 is assigned to eachcompartment 15, 16, 17, whereby, as illustrated schematically in thefigure, this may be an optionally installed air temperature sensor 27,27′ in the case of the refrigeration compartment 16 and freezercompartment 17, while the sensor 28 is assigned to the surface of theevaporator 24 in the case of the refrigeration compartment 14.

[0020] A regulator assembly 30 controls the operation of the compressor19, as well as the switch position of 22, 22′ by means of measuringsignals transmitted over the signal lines 29 by the sensors 27, 27′, 28.

[0021] The regulator assembly 30 moves the refrigerant flow throughbranch II by means of the measuring signal of the air temperature sensor27 of the standard refrigeration compartment 16, so that the temperaturein the standard refrigeration compartment 16 is at a value set by theuser. When a refrigerant flows through this circuit, the freezercompartment 17 and the refrigeration compartment 15 are also cooled inaddition to the standard refrigeration compartment 16. The coolingcapacities of the individual evaporators 24, 25, 26 are calculated sothat the cooling capacity of the evaporators 24, 26 are insufficient tocover the cooling requirement of its compartments 15, 17 during thethermostat-controlled operation of branch II by means of the measuringsignal of sensor 27.

[0022] When one of the temperature sensors 27, 28 detects a coolingrequirement, however, the sensor 27 does not, the regulator assembly 30will always operate the refrigeration system in the switch position ofthat for branch 1 or 111.

[0023] When the air temperature sensor 27 of standard coolingcompartment 16 and one of the air temperature sensors 28, 27′simultaneously detect a cooling requirement, arrangements may be made sothat the regulator assembly 30 ignores the detected result of the airtemperature sensor 28 or 27′ until the air temperature sensor 27 nolonger reports a cooling requirement. This means that all threecompartments are cooled until the standard refrigeration compartment 16has reached the holding temperature and subsequently continues to coolover one of the branches 1, 111 depending on the requirement.Alternative arrangements may be made so that the regulator assembly 30also considers the deviation of the temperature recorded by the airtemperature sensor 28 or 27′ of the holding temperature in such an eventfor the appropriate compartment 15 or 17 and that it changesoccasionally to branch I or 111, if the deviation of the measuredtemperature is greater than that of the air temperature sensor 27 fromthe measured holding temperature for the appropriate compartment thandepending on the fact if the excessive temperature is present in thefreezer compartment 17 or in the freezer compartment 15, andsubsequently again activates the branch when the excessive temperaturedeviation has been eliminated.

[0024]FIG. 3 shows a first example of an evaporator in a schematicillustration for the refrigerating appliance described in reference toFIGS. 1 and 2. The evaporator contains the abovementioned evaporators24, 25, 26, which are illustrated here assembled on a single supportplate, however, which may also be designed as separate components.

[0025] The branch II enters the evaporator 25 of the freezer compartmentat an inlet 31 and meanders essentially over its entire surface to ajunction 32 on the evaporator 26 of the freezer compartment. The linecoming from the evaporator 25 joins with branch I at this point, whichenters the evaporator 26 over an entry connection 33 and from thereessentially progresses over the entire surface of the evaporator 26. Theline finally reaches a connecting point 34 on the evaporator 24 of therefrigeration compartment and from there progresses to an outlet 35 overwhich the refrigerant is returned to the compressor 19.

[0026] The line between the connecting point 34 and the outlet 35 coolsonly a part of the surface of the evaporator 24, a line, whichprogresses from an inlet 36 of the evaporator 24 to the connecting point34 and belongs to branch III, uses the remaining surface. Throughsuitable selection of the position of the connecting point 34 on theevaporator 24, it may be defined how large the part of the surface ofthe evaporator 24 is which is also a part of the branches I and II andtherefore is also cooled along with the standard refrigerationcompartment 16 and freezer compartment 17. The cooling capacity in therefrigeration compartment 15 and the hazard of super-cooling of therefrigeration compartment may be limited by this design method duringthe operation of branches I and II.

[0027] The evaporators in FIG. 4 differ from those in FIG. 3 by theposition of the first connecting point 32. In the case of FIG. 4, thisis arranged at about half the length of the refrigerant line of theevaporators 26 so that the evaporator 26 of the freezer compartment isonly cooled over its entire surface during the operation of branch I,however, only at about half during the operation of branch II. The samedeliberations apply here as illustrated in reference to FIG. 3 for theevaporator 24 of the refrigeration compartment: The cooling capacity ofthe evaporator 26 may be limited during the operation of branch II by asuitable positioning of the connecting point 32 and thus avoidsuper-cooling of the freezer compartment during the operation of circuitII. Such a hazard may otherwise develop when the refrigerating applianceis operated at low ambient temperatures.

1. A refrigerating appliance (10) with at least one first (15), onesecond (16) and one third refrigerating area (17) for a low, an averageand/or a high storage temperature, of which each has an evaporator (24,25, 26), a compressor (19), a refrigerant circuit to supply compressedrefrigerant to the evaporators (24, 25, 26) and to return expandedrefrigerant to the compressor (19), and with at least one switchingelement (22, 22′) to selectively guide the refrigerant through one oftwo branches (I, II) of the refrigerant circuit, whereby the evaporators(24, 26) of the first and the third refrigerating areas (15, 17) aresequentially connected in the first branch (I), characterised in thatthe evaporators (24, 25, 26) of all three refrigerating areas (15, 16,17) are sequentially connected in the second branch (II).
 2. Therefrigerating appliance as claimed in claim 1, characterised in that thesecond branch (II) only extends over a part of the surface of theevaporator (26) of the third refrigerating area (17).
 3. Therefrigerating appliance as claimed in claim 1 or 2, characterised inthat the evaporator (26) of the third refrigerating area (17) is locatedin the second branch (II) between the evaporators (24, 25) of the firstand the second refrigerating area (15, 16).
 4. The refrigeratingappliance as claimed in any one of the preceding claims, characterisedin that the refrigerant circuit has a third branch (III), which containsonly the evaporator (24) of the first refrigerating area (15).
 5. Therefrigerating appliance as claimed in claim 4, characterised in that thefirst and the second branch (I, i t) extend only over a part of thesurface of the evaporator (24) of the first refrigerating area (15). 6.Evaporators for a refrigerating appliance as claimed in any one of thepreceding claims, with three connected evaporators (24, 25, 26) and atleast three connections (31, 33, 35), characterised in that a seriesconnection of the three evaporators (24, 25, 26) spans between two ofthe connections (31, 35).